Hugo Chavez has been president of Venezuela for 12 years -- and he remains popular. But the outspoken leader of the South American country is facing the toughest challenge of his electoral career from Henrique Capriles, and it comes at a time when Chavez is battling cancer.

Venezuela's President Hugo Chavez has returned to Cuba for more cancer treatment. Meanwhile, his political challenger has been out on the campaign trail. Venezuela's fractured opposition has united behind Henrique Capriles Radonski.

Venezuela's President Hugo Chavez has returned to Cuba for more cancer treatment. Meanwhile, his political challenger has been out on the campaign trail. Venezuela's fractured opposition has united behind Henrique Capriles Radonski.

Hugo Chavez has been president of Venezuela for 12 years -- and he remains popular. But the outspoken leader of the South American country is facing the toughest challenge of his electoral career from Henrique Capriles, and it comes at a time when Chavez is battling cancer.